WASET
    Chaghoub Soraya and  Zhang Xiaoyan,  Constant Factor Approximation Algorithm for p-Median Network Design Problem with Multiple Cable Types.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2020, vol. 163(7). 259 - 262
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/10011331.